Events

The nursery of Clark Farm and Cascade Foods asked our team to help design a pyrolysis equipment to support facilities for hazelnut shells so that this equipment can solve the pyrolysis of 10,000 tons of hazelnut shells per year and minimize the energy consumption of the equipment. We were tasked to provide many deliverables such as the reaction conditions of the hazelnut shell when pyrolysis occurs, amount of hazelnut shells feeding into the reactor, size of the reactor, analysis of the reaction products, subsequent combustion of biomass oil and gaseous products heat energy recovery, economic analysis, and safety analysis. We will present some of the findings by participating in the Engineering Virtual Expo. The engineering team found that the main composition of hazelnut shells consists of 42.9% lignin, 28.8% Cellulose, and 30.4% Hemicellulose; the shells are also composed of 9% moisture content based on the research of related literature. It was determined that a fast pyrolysis reaction and a fluidized bed reactor was the best condition and equipment for this process. Nitrogen gas will be added to the fluidized bed reactor as an inert gas and may reuse the nitrogen if the process is worth it. The primary energy consumption will be an electric heater using a resistance loop to release heat. After grinding, the hazelnut shells will continue to be fed to the reactor to react until their temperature reaches 500 degrees Celsius. Due to the rapid heating rate, the biochar content of the reaction product is 15%-25%, the biomass oil content is 55%-75%, and the non-condensable gas content is about 10%-20%. Both non-condensable gas and biomass oil leave the reactor in a gaseous state to mix it with air and entirely burn it. The heat released by the combustion vaporizes the deionized water so that the heat released by the steam can be used for hazelnut drying or nut roasting. With this energy recovery, the energy consumption of the factory can be greatly reduced because biochar can be used as a soil amendment for hazelnut growth to promote the retention of water and nutrients. Biochar can be sold after cooling down. Besides the core pyrolysis equipment, the team has considered multiple process ideas. For instance, we can implement a separation system to separate flammable gas and bio-oil, and bio-oil may be used for sale. Considering the sponsor company is in the food industry, the team will instead use a spray to mix the air for direct combustion for more economical purposes instead of recycling thermal energy. The project has its directions already in place, and the team is working on improving the design profitability and minimizing the energy cost. The goal is first to satisfy the treatment requirement, which is handling 10,000 tons per year from September to April through the design; Secondly, we will also strive to maximize energy recovery from hazelnut shells and char production.